Cooling device for anodes in metal vapor rectifiers



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U. LAMM Jan. 17, 1933.

COOLING DEVICE FOR ANODES IN METAL VAPOR RECTIFIERS Filed June 12. 1930I U/zo Lamm ber Patented Jan. 17, 1933 UNITED hiATES PATENT c erics UNOLAMIvL OF LUIDVIKA, SWEDEN, ASSIGNGE TO ALLMANNA SVENSKA ELEKTRISKAAKTIEBOLAGET, OF VASTERAfi, SWEDEN, A CGBPOBATION OF SWEDEN COOLINGDEVICE FOR ANODES EN METAL VAPOR RECTIFIERS Application filed June 12,1930, Serial No. 460,672, and in Sweden May 8, 1929.

In electric current rectifiers containing metal vapor, for instance,mercury vapor, as a conducting medium, it has been found to be ofimportance to keep the anodes a substantially constant, not too lowtemperature. As the energy dissipated at the anodes is substantiallyproportional to the current and thus highly. variable, it is necessaryto cool the anodes by some means which is readily adaptable to saidvarying conditions. it has already been proposed to use mercury, whichis vaporized inside the anode and then again cooled to condensation. Taearrangements previously used for this purpose have, however, not beenvery efficient. Generally the mercury vapor has been condensed againinside the rectifier receptacle, cooling tubes containing anothercirculating liquid being introduced into the lower portion of the anodesfor eilecting the condensation. "Where in some cases the mercury vaporhas been led outside the receptacle to be condensed there, there has,been a great risk of the packings around the anodes being damaged by thehot mercury vapor.

According to the present invention, the passage between the interior ofthe anode proper and the condensing device, which is situated outsidethe receptacle wall, is heat insulated against the packing in said wall,so that the latter is protected against undue heating.

For keeping the ebullition point of the mercury or other cooling liquidhaving a high such point as nearly constant as possible it is advisableto enclose a permanent gas or gas mixture in the interior of the anodeso as to keep the total pressure therein approximately constant. Such agas has a certain tendency to prevent the access of the mercury vapor tothe cooling surfaces intended to effect the condensation. In order toovercome such tendency certain steps are taken according to the presentinvention, as will be hereinafter described.

Two differentforms of the invention are illustrated in the accompanyingdrawing in Figs. 1 and 2, each of which shows an anode with coolingdevice in a vertical section.

In both figures, 1 represents an anode for a metal vapor rectifier,consisting for instance of pure iron, and 11 is an insulator therefor,inserted in the upper Wall ll of the rectifier receptacle where it isheld in place by a split ring 15 and surrounded by a packing 16 with aflange 17 so as to form a vacuum tight joint. A plurality of such anodesare generally combined in one receptacle. The anode is hollow, and itsinterior space is filled to a certain height with a cooling liquid 2,for instance mercury. The anode carries a'tubular extension 3,preferably integral therewith, and extending up wards through theinsulation 11 and through packing 13 with compression flange 12, adaptedto form a vacuum tight joint between the tube 3 and insulator 11. Thepackings 16 and 13 preferably contain mercury as principal sealingsubstance.

In order to protect the insulator 11 as well as the packings inside andoutside it against undue heating from the mercury vapor, the latter isled through a preferably central tube 5 surrounded by heat insulatingmaterial 4.

A portion of the tube 3 above the insulator and packings carries coolingribs 9 for effecting the condensation of the mercury vapor. If thiscooling portion of the tube is at the very top thereof and no particularsteps are taken, the heavy mercury vapor has a tendency to displace thepermanent gas enclosed, which is generally lighter, towards the top ofthe tube where it forms a cushion actin to prevent access of the vaporto the cooling portion. The low diffusion speed of the mercury vaporwhich is a consequence of its high specific gravity further aggravatesthis phenomenon. In order to overcome it, the central tube 5 for therising mercury vapor in Fig. 1 ends in a nozzle 7 forming together witha surrounding appropriately shaped tube 8 a jet apparatus which willmake the vapor carry forth the gas in the upper end of the tube 3 andcause it to circulate upwards through the tube 8 and downwards throughthe annular space between said tube and the tube 3. This annular space,being most adjacent to the cooling ribs 9, forms the condensing chamber,

from which the mercury flows down into the anode through the pipe 6. Thelatter is bent upwards at its lower end to form a liquid seal forpreventing the rising vapor from passing through said pipe.

n Fig. 2, the same result is achieved in another way. The tube 3 is hereextended above the cooling ribs 9 to form a particular chamber in whichthe gas displaced by the vapor may collect without disturbing thecondensation. This arrangement is simpler than that shown in Fig. 1 butnecessitates a greater total height of the anodes. The con densate mayin this case flow back through the tube 5.

As the arrangements described make the cooling action practicallyindependent of the physical properties of the enclosed gas, the lattermay be chosen exclusively with respect to its chemical properties so asto attack the cooling liquid and the walls of the anode and tubes in thesmallest possible degree. In using mercury as a cooling liquid, the gasmay preferably consist of an. inert gas or hydrogen.

I claim as my invention:

1. A mercury vapor rectifier comprising a vapor-containing receptacle,at least one hollow anode traversing the upper wall of said receptacle,a vacum-tight packing surrounding each of said anodes, a liquid having ahigh ebullition point inside said anodes adapted to be vaporized at thelower end and condensed at the upper end of said anodes, and a heatinsulating lining inside said anodes adjacent to said surroundingpacking.

2. A mercury vapor rectifier comprising a metallic vapor-containingreceptacle, a hollow anode traversing the upper wall of said receptacle,an insulator bushing surrounding said anode, vacuum-tight packingsbetween said anode and insulator and between said insulator and wall, aliquid having a high ebullition point inside said anode adapted to bevaporized at the lower end and condensed at the upper end of said anode,and a heat insulating lining inside said anode adjacent to the packingbetween the anode and insulator.

3. A mercury vapor rectifier comprising a vapor-containing receptacle,ahollow anode having an entirely closed inner space traversing the upperwall of said receptacle, cooling means surrounding said anode outsidesaid receptacle, a liquid having a high ebullition point and asubstantial amount of s both enclosed in said anode, and means insidesaid anode for guiding the current of vapor of said liquid to passclosely adjacent to the wall portion of the anode surrounded by saidcooling means.

4. A mercury vapor rectifier comprising a vapor-containing receptacle, ahollow anode having an entirely closed inner space traversing the uppewall of said receptacle, cooling means surrounding said anode outsidesaid receptacle, a liquid having a high ebullition point and a gasenclosed in said anode, a central rising tube for the vapor of saidliquid, a

nozzle forming the upper termination of said tube and a tube surroundingsaid nozzle to form a jet apparatus in which the gas and vapor are mixedbefore reaching said cooling means.

5. A mercury vapor rectifier comprising a vapor-containing receptacle, ahollow anode having an entirely closed inner space traversing the upperwall of said receptacle, cooling means surrounding said anode outsidesaid receptacle, a liquid having a high ebullition point and a gas inertwith respect to said liquid both enclosed in said anode, and meansinside said anode for guiding the current of vapor of said liquid topass closely adjacent to the wall portion of the anode surrounded bysaid cooling means.

In testimony whereof I have signed my name to this specification.

UNO LAMM.

